Patent Grant
6908636
Poultry processing is an area in which microbiological control is of vital importance. By the very nature of the processing involved there are numerous opportunities for the poultry to be exposed to various pathogens in the form of mobile bacteria such as for example Escherichia coli, Salmonella enteritidis, Salmonella typhimurim, Campylobacter jejuni, Campylobacter coli, Campylobacter lari, and in the form of biofilms such as for example Listeria monocytogenes, Pseudomonas fluorescens, Pseudomonas aeruginosa, Enterococcus faecium, and Staphylococcus aureus. The thought of handling, processing and consuming bacteria-infested poultry is revolting in the extreme.
Heretofore certain chlorine-based microbiocides have been proposed and used in an attempt to provide suitable sanitation in connection with poultry processing. Unfortunately while some chlorine-based microbiocides show some effectiveness, they possess a number of serious shortcomings. For one thing they are not as effective as one might wish. Secondly, they tend to be odorous and in many cases can exert a bleaching effect upon the poultry carcasses which can prove unpalatable to the consumer. Moreover, because of the spread of fecal matter associated with the evisceration of the fowl, fecal bacteria abound. This egregious condition in turn results in high nitrogen levels in the wash waters, and on wet surfaces such as cutting surfaces, conduits, tank surfaces, and other downstream equipment exposed one way or another to these wash waters. Unfortunately, the active chlorine species of certain chlorine-based microbiocides tend to react with the nitrogenous species to form chloroamines which are lachrymators as well as being corrosive to metallic surfaces. In fact, as little as 50 ppm of chlorine in aqueous washing tanks containing nitrogenous impurities can produce quantities of air-borne lachrymators that are intolerable to plant workers. Furthermore, the consumption of chlorine values in forming chloramines results in a significant loss of biocidal effectiveness inasmuch as the chloroamines are not biocidally-active species.
Clearly therefore a need exists for anew, more effective, economically feasible way of providing microbiological control in the poultry processing industry.
This invention fulfills the foregoing need by providing and utilizing in certain highly effective halogen-based microbiocides in the processing of poultry and in the disinfection of equipment, instruments, apparatus, and/or water used in the processing of poultry, and/or of carcasses and/or parts of poultry resulting from the processing of poultry. Microbiocidal agents used pursuant to this invention can be produced economically in straightforward processing from relatively low cost raw materials and because of their effectiveness, can provide microbiological control on an economical basis consistent with the needs of the industry.
In one of its embodiments this invention provides in the processing of poultry, the improvement which comprises disinfecting equipment, instruments, apparatus and/or water used in such processing, and/or carcasses and/or other parts of poultry resulting from such processing, with a halogen-based microbiocide which is:
Purely for convenience, the microbiocides of (I) described above when made from bromine chloride, bromine and chlorine, or bromine, chlorine, and bromine chloride, and a sulfamate source, are sometimes referred to hereinafter as “sulfamate-stabilized bromine chloride” even though technically the actual chemical species in the aqueous medium are most probably not bromine chloride molecules or sulfamate adducts or complexes of bromine chloride. Thus the designation “sulfamate-stabilized bromine chloride” is simply a shorthand way of referring to such compositions, and the designation does not signify, suggest, or imply anything about the actual chemical structure of the composition.
In preferred embodiments, the halogen-based microbiocide used in the above process is (A) abromine-based microbiocide comprising an overbased aqueous microbiocidal solution of one or more active bromine species, said species resulting from a reaction in water between bromine or bromine chloride, a mixture of bromine chloride and bromine, or a combination of bromine and chlorine in which the molar amount of chlorine is either equivalent to the molar amount of bromine or less than the molar amount of bromine, and a water-soluble source of sulfamate anion, or (B) an aqueous microbiocidal solution of at least one 1,3-dibromo-5,5-dialkylhydantoin in which one of the alkyl groups is a methyl group and the other alkyl group contains in the range of 1 to about 4 carbon atoms, or (C) both of (A) and (B) hereof. Thus in the embodiments of this invention wherein equipment, instruments, apparatus and/or water used in poultry processing is disinfected, and/or carcasses and/or other parts of poultry resulting from such processing are disinfected, “bromine-based” means any of the microbiocides referred to in this paragraph as (A), (B), or (C). In practice, the surfaces to be disinfected are contacted with the aqueous microbiocidal solutions of (A), (B), or (C) which of course contain amicrobiocidally-effective amount of the microbiocidal agent and/or microbiocidal hydrolysis product(s) thereof.
Such bromine-based microbiocides are more effective than chlorine-based microbiocides against various bacteria and biofilms. In addition, these bromine-based microbiocides tend to be less odorous than chlorine-based microbiocides, and are essentially devoid of unwanted bleaching activity. Moreover, while some of the bromine-based microbiocides may possibly react with nitrogenous species, such as are present in water and on surfaces associated with poultry processing, the resultant bromamines would also possess microbiological activity. Thus such side reactions would not materially decrease the microbiological effectiveness made available to the poultry processor by use of these bromine-based microbiocides. Furthermore, bromamines generally do not exhibit obnoxious properties toward workers in the processing plant whereas chloramines resulting from use of certain chlorine-based microbiocides under the same conditions tend to be powerful lachrymators.
As noted above, the halogen-based microbiocides of (I) above are microbiocidal solutions of one or more active halogen species, which solutions are derivative products in a aqueous medium such as water of bromine, chlorine, or bromine chloride, or any two or all three thereof and a water-soluble source of sulfamate anion. Likewise, the preferred bromine-based microbiocides of (A) above are microbiocidal solutions of one or more active bromine species, which solutions are derivative products in a aqueous medium such as water of bromine or bromine chloride, a mixture of bromine chloride and bromine, or a combination of bromine and chlorine in which the molar amount of chlorine is either equivalent to the molar amount of bromine or less than the molar amount of bromine, and a water-soluble source of sulfamate anion. To form these derivative products the components from which the derivative products are formed are brought together in an aqueous medium such as water, which medium or water, when forming the product, preferably is always at a pH of at least 7 and more preferably is always at a pH higher than 7, e.g., in the range of 10-14, by use of an inorganic base such as sodium hydroxide. When using a commercially-available product of this type (Stabrom® 909 biocide; Albemarle Corporation), the pH of the aqueous product as received is normally in the range of 13 to 14.
Similarly, the halogen-based microbiocides of (II) above are microbiocidal solutions of one or more active halogen species, which solutions are derivative products in an aqueous medium such as water of at least one 1,3-dihalo-5,5-dialkylhydantoin in which one of the halogen atoms is a chlorine atom and the other is a chlorine or bromine atom and the akyls are as described. Of the halogen-based microbiocides of (II) above, preferred are microbiocidal solutions of one or more active halogen species, which solutions are derivative products in an aqueous medium such as water of at least one 1,3-dihalo-5,5-dialkylhydantoin in which one of the halogen atoms is a bromine atom and the other is a chlorine atom (and the alkyls are as described). The bromine-based microbiocides of (III) above and of (B) above are microbiocidal solutions of one or more active bromine species, which solutions are derivative products in an aqueous medium such as water of at least one 1,3-dibromo-5,5-dialkylhydantoin in which the alkyls are as described. Upon dissolving in an aqueous medium such as water a 1,3-dihalo-5,5-dialkylhydantoin referred to in this paragraph, a transformation takes place so that active halogen (or bromine) species are present in the resultant solution.
The aqueous microbiocidal solutions used pursuant to the above embodiments of this invention can be formed in many cases by adding the microbiocidal agent itself (i.e., in undiluted form) or as a preformed concentrated aqueous solution thereof to water being used in one or more poultry processing operations (e.g., water flowing into chill tanks, or water already in chill tanks, etc.) to form a diluted microbiocidal solution of this invention which contacts the surfaces to be disinfected. Alternatively, a concentrated preformed aqueous solution of the microbiocidal agent can be applied directly to the surfaces to be disinfected (e.g., surfaces of cutting tables, or knives, or etc.), or more usually such concentrated solution would be mixed with water to form a more dilute solution of the microbiocidal agent which is applied to the surfaces to be disinfected and/or introduced into water being used in poultry processing operations. In short, the aqueous microbiocidal solutions used pursuant to these embodiments of the invention can be made in whole or in part from water already in use or to be used in the poultry processing operations, or can be made entirely from water separate from that used or to be used in the poultry processing. In each such case, the contacting of the aqueous microbiocidal solution however produced and/or applied to the surfaces results in effective disinfection.
At present the most preferred bromine-based microbiocide used in the practice of any embodiment of this invention is a water-soluble 1,3-dibromo-5,5-dialkylhydantoin in which one of the alkyl groups is a methyl group and the other is an alkyl group containing from 1 to about 4 carbon atoms, with 1,3-dibromo-5,5-dimethylhydantoin being the most preferred of all.
Various embodiments and features of this invention will be still further apparent from the ensuing description and appended claims.
One group of halogen-based microbiocides for use in disinfection of equipment, instruments, apparatus, and/or water used in the processing of poultry, and/or of carcasses and/or parts of poultry resulting from the processing of poultry pursuant to this invention is an aqueous microbiocidal solution of one or more active halogen species, said species resulting from a reaction in water between bromine, chlorine, or bromine chloride, or any two or all three thereof, and a water-soluble source of sulfamate anion. If sulfamic acid is used in forming this microbiocide, the solution should also be provided with a base, preferably enough base to keep the solution alkaline, i.e., with a pH above 7, preferably above about 10 and most preferably about 13 or above. The lower the pH, the more unstable the solution, and thus if the solution is prepared on site for immediate use, the use of a base is not essential. However, it is preferable to employ a concentrated microbiocidal solution manufactured elsewhere, and in such case the concentrated solution would be provided as an overbased solution with a pH of, say, about 13 or more. Often such concentrated solutions will contain over 50,000 ppm (wt/wt) of active halogen, preferably at least about 100,000 ppm (wt/wt) of active halogen, and sometimes as much as about 150,000 ppm (wt/wt) or more of active halogen, active halogen content being determinable by use of conventional starch-iodine titration.
One preferred group of this type is a bromine-based microbiocidal solution formed by reacting bromine or, more preferably bromine chloride, a mixture of bromine chloride and bromine, or a combination of bromine and chlorine in which the molar amount of chlorine is either equivalent to the molar amount of bromine or less than the molar amount of bromine, in an aqueous medium with sulfamic acid and/or a water-soluble salt of sulfamic acid. Except when made on site for immediate use, such solutions should be highly alkaline solutions typically with a pH of at least about 12 and preferably at least about 13, such pH resulting from use of a base such as sodium hydroxide or the like, in producing the solution. Concentrated solutions of this type are available in the marketplace, for example, Stabrom® 909 biocide (Albemarle Corporation). Processes for producing these concentrated aqueous microbiocidal solutions are described in commonly-owned U.S. Pat. No. 6,068,861, issued May 30, 2000, and 6,299,909 B1, issued Oct. 9, 2001, all disclosures of which are incorporated herein by reference.
It will be appreciated that even where the microbiocide is made from bromine chloride, a mixture of bromine chloride and bromine, or a combination of bromine and chlorine in which the molar amount of chlorine is either equivalent to the molar amount of bromine or less than the molar amount of bromine is used, the microbiocide is bromine-based as most of the chlorine usually winds up as a chloride salt such as sodium chloride since an alkali metal base such as sodium hydroxide is typically used in the processing to raise the pH of the product solution to at least about 13. Thus the chlorine in the product solution is not present as a significant microbiocide.
Another group of halogen-based microbiocides for use in these embodiments of this invention is one or more N,N′-halo-5,5-dialkylhydantoins in which one of the halogen atoms is chlorine and the other is bromine or chlorine, and in which the alkyl groups, independently, each contain from 1 to about 4 carbon atoms. Suitable compounds of this type include, for example, such compounds as 1,3-dichloro-5,5-dimethylhydantoin, 1,3-dichloro-5,5-diethylhydantoin, 1,3-dichloro-5,5-di-n-butylhydantoin, 1,3-dichloro-5-ethyl-5-methylhydantoin, N,N′-bromochloro-5,5-dimethylhydantoin, N,N′-bromochloro-5-ethyl-5-methylhydantoin, N,N′-bromochloro-5-propyl-5-methylhydantoin, N,N′-bromochloro-5-isopropyl-5-methylhydantoin, N,N′-bromochloro-5-butyl-5-methylhydantoin, N,N′-bromochloro-5-isobutyl-5-methylhydantoin, N,N′-bromochloro-5-sec-butyl-5-methylhydantoin, N,N′-bromochloro-5-tert-butyl-5-methylhydantoin, N,N′-bromochloro-5,5-diethylhydantoin, and mixtures of any two or more of the foregoing. N,N′-bromochloro-5,5-dimethylhydantoin is available commercially under the trade designation Bromicide® biocide (Great Lakes Chemical Corporation). Another suitable bromochlorohydantoin mixture is composed predominantly of N,N′-bromochloro-5,5-dimethylhydantoin together with a minor proportion by weight of 1,3-dichloro-5-ethyl-5-methylhydantoin. A mixture of this latter type is available in the marketplace under the trade designation Dantobrom® biocide (Lonza Corporation).
When a mixture of two or more of the foregoing N,N′-bromochloro-5,5-dialkylhydantoin biocides is used pursuant to this invention, the individual biocides of the mixture can be in any proportions relative to each other.
It will be understood that the designation N,N′ in reference to, say, N,N′-bromochloro-5,5-dimethylhydantoin means that this compound can be (1) 1-bromo-3-chloro-5,5-dimethylhydantoin, or (2) 1-chloro-3-bromo-5,5-dimethylhydantoin, or (3) a mixture of 1-bromo-3-chloro-5,5-dimethylhydantoin and 1-chloro-3-bromo-5,5-dimethylhydantoin. Also, it is conceivable that some 1,3-dichloro-5,5-dimethylhydantoin and 1,3-dibromo-5,5-dimethylhydantoin could be present in admixture with (1), (2), or (3).
An even more preferred system for use in the practice of these embodiments of this invention is a bromine-based microbiocidal solution of a 1,3-dibromo-5,5-dialkylhydantoin in which one of the alkyl groups is a methyl group and the other alkyl group contains in the range of 1 to about 4 carbon atoms. Thus these preferred biocides comprise 1,3-dibromo-5,5-dimethylhydantoin, 1,3-dibromo-5-ethyl-5-methylhydantoin, 1,3-dibromo-5-n-propyl-5-methylhydantoin, 1,3-dibromo-5-isopropyl-5-methylhydantoin, 1,3-dibromo-5-n-butyl-5-methylhydantoin, 1,3-dibromo-5-isobutyl-5-methylhydantoin, 1,3-dibromo-5-sec-butyl-5-methylhydantoin, 1,3-dibromo-5-tert-butyl-5-methythydantoin, and mixtures of any two or more of them. Of these biocidal agents, 1,3-dibromo-5-isobutyl-5-methylhydantoin, 1,3-dibromo-5-n-propyl-5-methylhydantoin, and 1,3-dibromo-5-ethyl-5-methylhydantoin are, respectively, preferred, more preferred, and even more preferred members of this group from the cost effectiveness standpoint. Of the mixtures of the foregoing biocides that can be used pursuant to this invention, it is preferred to use 1,3-dibromo-5,5-dimethylhydantoin as one of the components, with a mixture of 1,3-dibromo-5,5-dimethylhydantoin and 1,3-dibromo-5-ethyl-5-methylhydantoin being particularly preferred. The most preferred member of this group of microbiocides is 1,3-dibromo-5,5-dimethylhydantoin. This compound is available in the marketplace in tablet or granular form under the trade designations Albrom® 100T biocide and Albrom® 100PC biocide (Albemarle Corporation).
When a mixture of two or more of the foregoing 1,3-dibromo-5,5-dialkylhydantoin biocides is used pursuant to this invention, the individual biocides of the mixture can be in any proportions relative to each other.
Methods for producing 1,3-dibromo-5,5-dialkylhydantoins are known and reported in the literature.
If desired, the 1,3-dihalo-5,5-dialkylhydantoins can be dissolved in a suitable innocuous, harmless, water-soluble organic solvent with or without water to form a solution which can be applied to surfaces of equipment, instruments, or apparatus. Depending upon the solvent used, the surfaces can then be further washed with clean water to remove residues from such solvent. Besides increasing the amount of 1,3-dihalo-5,5-dialkylhydantoin that can be put into solution thus facilitating formation of a concentrated solution, e.g., on the premises of the poultry processing, such a concentrated solution when diluted such as by addition to process water being used on the premises possesses microbiocidal activity from the 1,3-dihalo-5,5-dialkylhydantoin. Thus aqueous solutions used pursuant to this invention can contain suitably small amounts of an innocuous, harmless, water-soluble organic solvent, which non-toxic, at least at the dosage levels involved, such as acetonitrile.
In cases where extremely powerful biocidal activity is desired such as during periodic cleaning and disinfection operations, concentrated aqueous solutions of the microbiocides of this invention can be directly applied to surfaces of poultry processing equipment, instruments and/or apparatus infested with pathogenic microorganisms. Such concentrated solutions can contain, for example, as much as 150,000 ppm or 160,000 ppm or more of active bromine, and as much as about 66,667 ppm or about 71,111 ppm of active chlorine, as determinable by conventional starch-iodine titration. If desired, a portion of such concentrated solution can be diluted with any suitable amount of water before application directly to the surfaces of such poultry processing equipment, instruments and/or apparatus, provided of course that the diluted solution still contains a microbiocidally-effective amount of active bromine species for the use at hand. Also, concentrated solutions of this invention can be added to and thus used in diluted form in process water being used in poultry processing operations, such as for example, in water flowing through conduits, in water flowing into or being maintained in tanks, and in water being used in spraying equipment.
The amount (concentration) of the selected microbiocide utilized in the practice of this invention will vary depending on various factors such as the particular microbiocide being used, the nature and frequency of prior microbiocidal treatments, the types and nature of the microorganisms present, the amount and types of nutrients available to the microorganisms, the nature and extent of cleansing actions, if any, taken in conjunction with the microbiocidal treatment, the surface or locus of the microorganisms being treated, and so on. In any event, a microbiocidally-effective amount of the diluted aqueous solution of the microbiocide of this invention will be applied to or contacted with the microorganisms. Typically the diluted solution will contain a microbiocidally-effective amount of active halogen in the range of about 2 to about 1000 ppm (wt/wt), preferably in the range of about 2 to about 500 ppm (wt/wt), and more preferably in the range of about 25 to about 250 ppm (wt/wt), active halogen being determinable by use of the conventional DPD test procedure. If the actual active halogen in the solution consists of active chlorine, the concentration of the diluted solution used is preferably at least two to three times higher than the minimums of the foregoing ranges. In the case of the 1,3-dibromo-5,5-dialkylhydantoins used pursuant to this invention, a particularly preferred range for use in ordinary situations (e.g., washing hard surfaces such as tables, walls, floors, conveyor machinery or parts thereof such as converor belts or shackles, and knives or cutting blades) is in the range of about 50 to about 150 ppm (wt/wt) of active bromine. When contacting poultry carcasses or edible parts thereof with aqueous solutions formed from at least one 1,3-dibromo-5,5-dialkylhydantoin used pursuant to this invention, it is especially preferred to use in the water for washing or otherwise contacting the poultry carcasses or edible parts thereof, a microbiocidally effective amount of active bromine that does not significantly or appreciably bleach the skin of the caracass or have a significant or appreciable adverse effect upon the organleptic taste of cooked meat from the poultry such as the breast meat and thigh meat. Such amount is typically within the range of about 0.5 to about 30 ppm (wt/wt) and preferably in the range of about 5 to about 25 ppm (wt/wt) of active bromine as determinable by the DPD test procedure. Similar ranges are deemed applicable if using sulfamate-stabilized bromine chloride in these carcass washing operations. It will be understood that departures from the foregoing ranges can be made whenever deemed necessary or desirable, and such departures are within the spirit and scope of this invention.
Consequently, depending upon the way in which the microbiocide of this invention is being used, a microbiocidally-effective amount of the microbiocides of this invention can extend from as little as about 2 ppm up to as high as the maximum water solubility of the particular active halogen microbiocidal agent being used, at the temperature at which such active halogen microbiocidal agent is being used.
As can be seen from the above, there are two different types of procedures that are used for determining active halogen content, whether active chlorine, active bromine or both. For measuring concentrations in the vicinity of above about, say, 500 ppm or so (wt/wt) of active bromine or, say, above about 1100 ppm of active chlorine, starch-iodine titration is the preferred procedure. On the other hand, where concentrations are below levels in these vicinities, the conventional DPD test procedure is more suitable, as this test is designed for measuring very low active halogen concentrations, e.g., active chlorine concentrations in the range of from zero to about 11-12 ppm (wt/wt) or active bromine concentrations in the range of from zero to about 5 ppm (wt/wt). In fact, where the actual concentration of active chlorine is between, say, about 11-12 ppm and about 1100 ppm (wt/wt), or the where the actual concentration of active bromine is between, say, about 5 ppm and about 100 ppm (wt/wt), the test sample is typically diluted with pure water to reduce the actual concentration to be in the range of about 4 to about 11-12 ppm in the case of active chlorine and to be in the range of about 2 to about 5 ppm in the case of active bromine before making the DPD analysis. It can be seen therefore that while there is no critical hard-and-fast concentration dividing line between which procedure to use, the approximate values given above represent a practical approximate dividing line, since the amounts of water dilution of more concentrated solutions when using the DPD test procedure increase with increasing initial active halogen concentration, and such large dilutions can readily be avoided by use of starch-iodine titration when analyzing the more concentrated solutions. In short, with suitably dilute solutions use of the DPD test procedure is recommended, and with more concentrated solutions use of starch-iodine titration is recommended.
The starch-iodine titration procedure for determination of active halogen has long been known. For example, chapter XIV of Willard-Furman, Elementary Quantitative Analysis, Third Edition, D. Van Nostrand Company, Inc., New York, Copyright 1933, 1935, 1940 provides a description of starch-iodine titration. While details of standard quantitative analytical procedures for determination of active halogen in such product solutions by starch-iodine titration may vary from case to case, the results are normally sufficiently uniform from one standard procedure to another as not to raise any question of unreliability of the results. A recommended starch-iodine titration procedure is as follows: A magnetic stirrer and 50 milliliters of glacial acetic acid are placed in an iodine flask. The sample (usually about 0.2-0.5 g) for which the active halogen is to be determined is weighed and added to the flask containing the acetic acid. Water (50 milliliters) and aqueous potassium iodide (15%, wt/wt; 25 milliliters) are then added to the flask. The flask is stoppered using a water seal. The solution is then stirred for fifteen minutes, after which the flask is unstoppered and the stopper and seal area are rinsed into the flask with water. An automatic buret (Metrohm Limited) is filled with 0.1 normal sodium thiosulfate. The solution in the iodine flask is titrated with the 0.1 normal sodium thiosulfate; when a faint yellow color is observed, one milliliter of a 1 wt % starch solution in water is added, changing the color of the solution in the flask from faint yellow to blue. Titration with sodium thiosulfate continues until the blue color disappears. The amount of active halogen is calculated using the weight of the sample and the volume of sodium thiosulfate solution titrated. In this way, the amount of active halogen such as active chlorine or active bromine in an aqueous product solution, regardless of actual chemical form, can be quantitatively determined.
The standard DPD test for determination of low levels of active halogen is based on classical test procedures devised by Palin in 1974. See A. T. Palin, “Analytical Control of Water Disinfection With Special Reference to Differential DPD Methods For Chlorine, Chlorine Dioxide, Bromine, Iodine and Ozorie”, J. Inst. Water Eng., 1974, 28, 139. While there are various modernized versions of the Palin procedures, the recommended version of the test is fully described in Hach Water Analysis Handbook, 3rd edition, copyright 1997. The procedure for “total chlorine” (i.e., active chlorine) is identified in that publication as Method 8167 appearing on page 379, Briefly, the “total chlorine” test involves introducing to the dilute water sample containing active halogen, a powder comprising DPD indicator powder, (i.e., N,N′-diethyldiphenylenediamine), KI, and a buffer. The active halogen species present react(s) with KI to yield iodine species which turn the DPD indicator to red/pink. The intensity of the coloration depends upon the concentration of “total chlorine” species (i.e., active chlorine”) present in the sample. This intensity is measured by a calorimeter calibrated to transform the intensity reading into a “total chlorine” value in terms of mg/L Cl2. If the active halogen present is active bromine, the result in terms of mg/L Cl2 is multiplied by 2.25 to express the result in terms of mg/L Br2 of active bromine.
In greater detail, the DPD test procedure is as follows:
1. To determine the amount of species present in the water which respond to the “total chlorine” test, the water sample should be analyzed within a few minutes of being taken, and preferably immediately upon being taken.
2. Hach Method 8167 for testing the amount of species present in the water sample which respond to the “total chlorine” test involves use of the Hach Model DR 2010 colorimeter. The stored program number for chlorine determinations is recalled by keying in “80” on the keyboard, followed by setting the absorbance wavelength to 530 nm by rotating the dial on the side of the instrument. Two identical sample cells are filled to the 10 mL mark with the water under investigation. One of the cells is arbitrarily chosen to be the blank. To the second cell, the contents of a DPD Total Chlorine Powder Pillow are added. This is shaken for 10-20 seconds to mix, as the development of a pink-red color indicates the presence of species in the water which respond positively to the DPD “total chlorine” test reagent. On the keypad, the SHIFT TIMER keys are depressed to commence a three minute reaction time. After three minutes the instrument beeps to signal the reaction is complete. Using the 10 mL cell riser, the blank sample cell is admitted to the sample compartment of the Hach Model DR 2010, and the shield is closed to prevent stray light effects. Then the ZERO key is depressed. After a few seconds, the display registers 0.00 mg/L Cl2. Then, the blank sample cell used to zero the instrument is removed from the cell compartment of the Hach Model DR 2010 and replaced with the test sample to which the DPD “total chlorine” test reagent was added. The light shield is then closed as was done for the blank, and the READ key is depressed. The result, in mg/L Cl2 is shown on the display within a few seconds. This is the “total chlorine” level of the water sample under investigation.
In the practice of this invention the microbiocidal system can be used in various ways. For example, a microbiocidally effective amount of a microbiocide of this invention, preferably a bromine-based microbiocidal system, is applied to the locus of the microorganisms to be eradicated or controlled so that the microbiocidal system comes in contact with these microorganisms. The application can be made by thorough application by pouring, spraying, wet mopping, flooding, and/or wet wiping infested or potentially infested surfaces or areas of the processing equipment and environs such as flooring, walls, tables, conveyors, stanchions, conduits, tanks, and drains with a biocidally-effective amount of an aqueous solution the microbiocide. Where applicable and possible, portions of the processing apparatus can be immersed in an aqueous solution of the microbiocide, with temporary disassembly, if necessary. Such applications should be conducted routinely on a frequency sufficient to ensure that exposure of the poultry being processed to dangerous microorganisms, such as bacteria and biofilms is prevented to the greatest extent possible. For best results these operations should be conducted in conjunction or association with thorough cleaning operations such as scrubbing, scouring, scraping and, otherwise removing infestations of biofouling or biofilms, whether visible or invisible. After contacting the microorganisms with the microbiocide for a suitable period of time to ensure penetration into polysaccharide slimes and other defense mechanisms of various species of these microorganisms, the entire disinfected area should be washed, e.g., hosed down, with clean water and preferably the washings themselves should be disinfected with additional microbiocide of this invention, preferably a bromine-based microbiocide, before discharge. The contact times will of course vary depending upon the frequency and thoroughness of the cleaning and disinfection operations and the identity and concentration of the particular microbiocidal solution being employed. Generally speaking contact times may fall in the range of from about a few minutes to a few hours, but any period of time that effects the eradication or control of the microbial population in the poultry processing areas should be used and is within the scope of this invention.
Another mode of applying the microbiocidally-effective amounts of solid-state microbiocides of these embodiments of the invention is to cause the microbiocide to be leached into water streams passing through conduits and into tanks or other washing devices utilized in the processing of the poultry. For example, suitable solid forms of the microbiocide, preferably a bromine-based microbiocide, such as tablets, briquettes, pellets, nuggets, or granules are placed in suitable feeding devices through which a stream of water is passed. The passage of the water through the bed of the microbiocide results in the stream continuously dissolving small quantities of the microbiocide to thereby provide microbiocidally effective amounts of the microbiocide in the water. 1,3-Dibromo-5,5-dimethylhydantoin is especially preferred for use in this mode of application because of its relatively low solubility and thus relatively slow rate of dissolution in water at ambient room temperatures. This translates into relatively long periods of use before need of refilling the device holding the solids. By way of example, the solubility of 1,3-dibromo-5,5-dimethylhydantoin in water at 75° F. (ca. 24° C.) is 405 ppm expressed as Cl2 whereas the solubilities of N,N′-bromochloro-5,5-dimethylhydantoin and of the commercial mixture of N,N′-bromochloro-5,5-dimethylhydantoin and 1,3-dichloro-5-ethyl-5-methylhydantoin at the same temperature are, respectively, 890 ppm and 1905 ppm, both expressed as Cl2.
An especially cost-effective, operationally efficient, and highly preferred way of forming aqueous microbiocidal solutions of one or more 1,3-dibromo-5,5-dialkylhydantoins in which one of the alkyl groups is a methyl group and the other alkyl group contains in the range of 1 to about 4 carbon atoms, most preferably 1,3-dibromo-5,5-dimethylhydantoin, (“dibromodialkylhydantoin(s)”) comprises passing water through a bed of one or more such dibromodialkylhydantoin(s) in granular, nugget, pellet, tablet or other non-powdery particulate form (“bed”) disposed in a canister, tank, or other similar vessel (“tank”). Preferably the tank has a pressure sealable port at its upper portion for periodically replenishing the contents of the bed, and the water is caused to flow upwardly through a portion of the bed. More preferably, the tank is elongated in an upward direction so that the bed is longer from top to bottom than from side to side, this upward water flow is dispensed into the bed to flow upwardly through only a lower portion of the bed, and thence substantially horizontally through a port disposed between the lower and the upper portions of the bed and tank. In this way the upper portion of the bed serves as a reserve supply of contents of the bed which automatically feeds into the lower portion of the bed under gravity a as the lower portion of the bed is slowly but substantially uniformly dissolved away in the water flow. Thus in this operation the water flow is preferably at least a substantially continuous flow, and most preferably, is a continuous flow. Methods for producing granules, tablets or other non-powdery particulate forms of 1,3-dibromo-5,5-dimethylhydantoin are described in detail in commonly-owned copending applications PCT/US 01/01541, 01/01545, and 01/01585, all filed Jan. 17, 2001, each claiming priority based on respective earlier-filed corresponding U.S. applications. Excellent process technology for producing 1,3-dibromo-5,5-dimethylhydantoin for use in making such granules, tablets or other non-powdery particulate forms is described in detail in commonly-owned copending application PCT/US 01/01544, filed Jan. 17, 2001, claiming priority based on an earlier-filed corresponding U.S. application. The disclosures of each such PCT and U.S. application is incorporated herein by reference. Particularly preferred apparatus for use in conjunction with such granules, tablets or other non-powdery particulate forms of these dibromodialkylhydantoin(s) in forming aqueous microbiocidal solutions thereof is available from Neptune Chemical Pump Company, a division of R.A. Industries, Inc., Lansdale, Pa. 19446, as “Bromine Feeders” Models BT-15, BT-40, BT42, BT-80, BT-160, BT-270, and BT-350, or equivalent. Excellent results are achieved using combinations of Model BT-40 with granules of 1,3-dibromo-5,5-dimethylhydantoin Albrom® 100 biocide available from Albemarle Corporation. Single charges of such microbiocides in tablet or granular form in such device can provide continuous highly-effective microbiocidal activity in bodies of end use water at ordinary outdoor temperatures for as long as five (5) months without need for replenishment.
In the case of the more water-soluble microbiocides used pursuant to this invention, another suitable method of effecting contact between the microbiocide and the microorganisms is to pump an aqueous solution containing a microbiocidally-effective amount of the microbiocide through the conduits and into the tanks or other washing devices, such as scalding tanks and chill tanks, utilized in the processing of the poultry. Variants of this procedure include dispensing portion-wise as by gravity dripping an aqueous solution of the microbiocide directly into a tank or other vessel in which poultry are to be or are being processed.
A further mode of application pursuant to these embodiments of the invention involves applying to or contacting the poultry itself, typically promptly before and/or after slaughter, with an aqueous solution of the microbiocide. After providing a suitable contact time to eradicate bacteria on the surfaces of the poultry, the poultry can then be washed down to remove both the excess microbiocide and the dispatched microbial population from the exposed surfaces of the fowl itself. The internal organs of the fowl after slaughter can also be treated and washed down in the same manner. The application(s) of the microbiocidal solution(s) in this manner can take any suitable form, e.g., use of aqueous sprays containing a microbiocidally-effective amount of the microbiocide being used, or immersion of the fowl or internal organs thereof in one or more tanks containing aqueous solutions of microbiocidally-effective amounts of the microbiocide being used.
Preferably two or more of the foregoing methods of application of the microbiocides of this invention are used. Thus in a preferred embodiment a microbiocide of these embodiments of the invention, preferably an aqueous bromine-based microbiocidal solution, is applied by (i) periodically contacting at least portions, if not all, of the poultry processing apparatus to disinfection or sanitization with a microbiocidally-effective amount of an aqueous solution of at least one microbiocide of these embodiments of the invention, preferably a bromine-based microbiocide, and (ii) contacting the exposed surfaces of the poultry with a microbiocidally-effective amount of an aqueous solution of at least one microbiocide of these embodiments of the invention, preferably a solution of abromine-based microbiocide, before and/or after, preferably after, dispatching the fowl. In another preferred embodiment, a microbiocide of these embodiments of the invention, preferably an aqueous bromine-based microbiocidal solution, is applied by (i) periodically contacting at least portions, if not all, of the poultry processing apparatus to disinfection or sanitization with a microbiocidally-effective amount of an aqueous solution of at least one microbiocide of these embodiments of the invention, preferably a bromine-based microbiocide, and (ii) contacting the edible portions and/or internal organs of the dispatched fowl with a microbiocidally-effective amount of an aqueous solution of at least one microbiocide of these embodiments of the invention, preferably a solution of a bromine-based microbiocide.
Particularly preferred processes of this invention are those wherein the fowl are processed by a series of steps which comprise the following: (a) suspending the fowl in moving clamps or shackles, (b) stunning, but not killing, the fowl such as by use of a suitable gas, or by contacting at least the heads of the fowl with a water-applied electric shock to stun the fowl, e.g., by immersing the heads in a water bath carrying a suitable current to effect the stunning, (c) cutting the jugular veins and/or carotid arteries at the neck of the stunned fowl either manually with a knife or automatically with a mechanical cutting device, (d) draining blood from the carcasses, (e) scalding the birds with hot water, e.g., in a scalding tank, to facilitate feather removal, (f) defeathering the fowl, (g) removing the heads and feet from the fowl, (h) eviscerating the fowl either manually with a knife, or automatically with mechanical evisceration apparatus, (i) separating the viscera from the carcasses, (j) washing the carcasses, and (k) chilling the carcasses, e.g., in water such as by passage of the carcasses through at least one and often two chill tanks, or by air chilling. The scalding step will typically be conducted at water temperatures in the range of about 50 to about 60° C., with the lower temperatures being preferred for retention of normal yellow-colored skin. The higher temperatures will more usually be used in connection with turkeys and spent egg-layer hens. The chilling temperatures used will typically reduce the carcass temperature to below about 40° C., with final temperatures of the finished carcasses for shipment being as low as about −2° C. Other steps can be included and in some cases one or more of the steps (a) through (j) may be altered or revised or the sequence of the steps may to some extent be altered or revised, to adapt to given circumstances. Examples of extra steps that may be included are inspection steps, e.g., by governmental regulatory personnel, and wax-dipping in the case of water fowl to enhance the extent of defeathering. Inspections are often conducted subsequent to the evisceration step, such as before separating the viscera from the carcasses. Wax dipping will typically be used when processing waterfowl, the feathers of which typically are more difficult to remove than, say, chickens. Wax dipping will typically be performed directly after use of feather-picking machines which utilize rubber “fingers” to beat off the feathers. The wax dipping step will typically involve dipping the partially defeathered carcass into a molten wax contained in a tank, allowing the wax to harden on the carcass, and then removing the wax coating as by peeling it off along with feathers embedded in the wax. This operation can be repeated as desired, before proceeding to the next step in the process, e.g., removal of the heads and feet. One illustrative example of a suitable revision of the sequence of steps, would be to conduct step (g) before step (d) instead of after step (f). Upon a reading of this disclosure, other suitable sequence revisions may well become obvious to one of ordinary skill in the art, and thus need not be further elaborated upon here.
In the above processing, the microbiocidal action of the microbiocides of these embodiments of the invention, preferably one or more applicable bromine-based microbiocides used pursuant to this invention, can be applied at any of a variety of suitable stages in the operation. For example, an applicable microbiocidal solution of this invention can be applied to any or all of the processing equipment used including knives, conveying apparatus, the surfaces of emptied scaling tanks, defeathering apparatus, (e.g., rubber “fingers” etc.), knives and mechanical apparatus used for cutting or eviscerating the fowl, all surfaces that come in contact with the blood or the viscera of the fowl, including tables, conveyor belts, etc., and all surfaces that come in contact with the carcasses after separation of the viscera therefrom. The applicable sanitizing solutions of this invention can be applied to by immersion, spraying, flooding, or any other way ofensuring that the microbiocidally-effective solution contacts the surfaces that contain or are exposed to the undesirable microorganisms such as bacteria and/or biofilm (biofouling).
Another way by which, in the above processing the microbiocidal action of the applicable microbiocides of this invention, preferably one or more applicable bromine-based microbiocides used pursuant to this invention, can be applied involves including a microbiocidally-effective amount of the microbiocide to the water being used at one or more stages of the processing. Thus the water in the scalding tank(s) and/or in the chill tank(s) can be so treated. Another mode is to include a microbiocidally-effective amount of the microbiocide to the water used in washing the carcasses and the viscera at various points where these parts are handled, separated, and/or processed. The dosage levels at these different points in the processing can be the same or different as deemed necessary or desirable.
The practice and advantages of this invention are illustrated by the following non-limiting Examples.
Comparative tests were conducted to determine the effect on poultry carcass bacteria (Escherichia coli field strain) during a normal 1.5-hour chill tank immersion in water containing different microbiocidal compositions. The effect of these treatments on the residual chill tank water was also investigated. Carcasses were first immersed in a warm bath containing 104 E coli per mL of liquid. Carcasses were then immersed in chill tanks containing normal organic fluids (blood, fat, skin, and meat particles) and containing one of the respective microbiocidal compositions under test. Total bacteria count of whole bird (both inside and outside) was used to determine efficacy of various microbiocidal compositions. The microbiocidal compositions tested were Aquatize® biocide (Bioxy Incorporated, 3733 National Drive, Suite 115, Raleigh, N.C. 27612-4845), sodium hypochlorite (Clorox® bleach), sodium bromide (supplied as a 40% solution in water), combinations of sodium hypochlorite and sodium bromide, and a concentrated alkaline aqueous solution produced from bromine chloride and sulfamate anion (SSBC) (Stabrom® 909 biocide; Albemarle Corporation).
The trial events and experimental design used were as follows:
Table 1 presents the experimental design of this group of tests.
1Negative Control contained contaminated (bacteria 2.67 × 105 per mL) water.
2Positive Control is normal poultry industry practice of adding 50 ppm Cl2 equivalent.
Tables 2-4 show, respectively, the method of determining the dilution levels for achieving 50 ppm, 100 ppm, and 150 ppm Cl2 equivalents in the case of the chill tank solutions formed from Clorox® bleach solution and a 40% water solution of sodium bromide.
Calculations for dilutions using the other biocides of this group that were tested were based on the following: Aquatize® biocide is a solution containing 3.67% sodium chlorite, and Stabrom® 909 biocide solution, it was calculated as 1.57 times Cl2 equivalent level. The results of this group of tests are summarized in Tables 5-7.
1The value represents an average of 10 birds per treatment.
2Test group 1 carcass contained 2.67 × 105 total bacteria count.
1The value represents an average of 10 birds per treatment.
2Test group 1 carcass contains 2.67 × 105 total bacteria count.
1The value represents bacteria count per mL of treatment water.
The procedure of Example 1 was repeated except that the materials tested for microbiocidal activity were (a) sodium hypochlorite (Clorox® bleach), (b) the combination of sodium bromide and sodium hypochlorite, and (c) 1,3-dibromo-5,5-dimethylhydantoin (DBDMH), 100 birds were used in this group of tests, and the chill water was composed per liter of 950 mL of water, 50 mL of blood, 10 g of ground abdominal fat, 10 g of meat particles, and 10 g of skin with fat.
The experimental design used in this group of tests is summarized in Table 8.
1Negative control contained contaminated (bacteria 2.67 × 105 per mL) water.
2Positive control is normal poultry industry practice of adding 50 ppm chlorine.
The microbiocidal solution of this invention was prepared in the following manner:
Table 9 summaries the results obtained in this group of tests.
1The value represents bacteria count per mL of treatment water.
2Negative control contained contaminated (bacteria 2.67 × 105 per mL) water.
3Positive control is normal poultry industry practice of adding 50 ppm chlorine.
This group of tests was conducted to determine the effect of Clorox® bleach, Aquatize® biocide, and 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) on carcass bacteria (Escherichia coli field strain) residual after 1.5-hour in a chill tank “soup”. Tests were conducted with soups at pH 7, pH 8 and pH 9 (adjusted by trisodium phosphate) for whole bird bacteria counts. Tests at pH 8 were conducted for individual bacteria counts.
In general the tests involved normal processing of 56-day-old birds and immersing the carcasses first in a warm bath containing 104 per mL Escherichia coli, 104 per mL Salmoella enteritidis, 104 per mL Pseudomonas aeruginosa, 104 per mL Campylobacter jejuni, and 104 per mL spoilage bacteria each from three strains (Listena monocytogenes and Shigella sonnei). The carcasses were then immersed in a chill tank “soup”, containing normal organic fluids (blood, fat, skin, and meat particles) and containing the microbiocides on the test.
Tables 10 and 11 summarize the experimental design of these group of test.
The bacteria stock solution used for this group of tests was prepared by growing each bacteria sample in the appropriate broth shown in Table 12. Each such broth had a volume of at least 500 mL and the bacteria were allowed to grow for at least 6 hours. The containers were observed and not allowed to develop a heavy, cloudy visual appearance which would indicate that the growth had developed for too long a period. Thus the solutions had the appearance of only being foggy or somewhat unclear.
S. sonnei
L. mono-
cytogenes
E. coli
S. enteritidis
P. aeruginosa
C. jejuni
1
Shigella sonnei, Listeria monocytogenes, Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa, and Campylobacter jejuni.
The microbiocidal solution of this invention was prepared in the following manner:
1. To form a stock solution, 100 g of 1,3-dibromo-5,5-dimethylhydantoin (DBDMM) was stirred into 10 liters (10,000 mL) of water for 20 minutes. After filtration, the resulting clear solution contains 1300 mg per liter as Br2. This corresponds to 580 mg per liter (or 580 ppm Cl2) when expressed as Cl2.
2. The chill water solution of DBDMH having a content of 10 ppm of Cl2 equivalent was formed by mixing 175 mL of the above stock solution with 10 liters (10,000 mL) of the above prepared chicken chill water solution. The chill water solution of DBDMH containing 20 ppm Cl2 equivalent and 150 ppm Cl2 equivalent were prepared in the same manner except that 350 mL of the above stock solution were mixed with another 10-liter portion of the above prepared chicken chill water solution.
Table 13 shows the composition of the “chicken soup” used in these tests.
1The combined material was chilled overnight.
2The material was ground and aggressively stirred prior to use.
The procedure used for whole bird wash sampling was as follows:
Quantitative or qualitative determinations for bacterial organisms were conducted according to the following methodologies: Aerobic plate counts—Counting rules according to BAM 8th ed., Chapter 3. Coliform and E. coli counts—AOAC, 991.14, Petrifilm. Salmonella—AOAC 986.35, ELISA presumptive screen. Salmonella—USDA LC-75, incidence. Campylobacter—USDA LC-69, incidence. Listeria—USDA LC-57, incidence.
In greater detail the trial events and experimental design used in this group of tests were as follows:
The results of this group of tests are summarized in Tables 14 and 15.
1Each value represents 50 birds per treatment.
S. sonnei
L. monocytogenes
E. coli
S. enteritidis
P. aeruginosa
C. jejuni
1
Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa, Campylobacter jejuni, listeria monocytogenes, and Shigella sonnei
2NOTE: Cross contamination is more likely in a processing environment where birds were processed and samples taken for individual culture determination.
3Each value represents 25 birds per treatment.
A study was conducted to determine the effect of Clorox® bleach, and 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) on carcass bacteria residual after 1.5 hour in a chill tank solution and spoilage 20-day shelf life longevity (caused by bacteria contamination). Tests were conducted at pH 8 (adjusted by trisodium phosphate). Skin pigmentation (Minolta Color Meter L value or Lightness, a value or redness and b value or yellowness) were determined before and post-processing.
In general the study involved normal processing of 56-day-old birds, immersing carcasses first in a warm bath containing 104 per mL Escherichia coli, 104 per mL Sailmonella enteritidis, 10 per mL Pseudomonas aeruginosa, 104 per mL Campylobacter jejuni, and 104 per mL spoilage bacteria each from three strains (Listeria monocytogenes and Shigella sonnel). Carcass were then immersed in a chill tank “soup”, containing normal organic fluids (blood, fat, skin, and meat particles) and containing various disinfectants (termed test materials).
Four test groups of birds were tested at pH 8 for whole bird bacteria counts. Table 16 sets forth the experimental design for these whole bacteria count tests.
A DBDMH stock solution and test solutions, a bacteria stock solution, and a “chicken soup” were prepared as in Example 3. In addition, the bacterial broth treatments, the whole bird wash sampling procedure, and the methodologies used for quantitative or qualitative determinations for bacterial organisms were conducted as in Example 3.
In greater detail the trial events and experimental design used in this group of tests were as follows:
The results of these tests are summarized in Tables 17-30.
1NOTE: Means within a row without a common superscript are significantly different (P < 0.05) as determined by Least Significant Difference.
1NOTE: Means within a row without a common superscript are significantly different (P < 0.05) as determined by Least Significant Difference.
S. sonnei
L. monocytogenes
E. coli
S. enteritidis
P. aeruginosa
C. jejuni
S. sonnei
L. monocytogenes
E. coli
S. enteritidis
P. aeruginosa
C. jejuni
S. sonnei
L. monocytogenes
E. coli
S. enteritidis
P. aeruginosa
C. jejuni
S. sonnei
L. monocytogenes
E. coli
S. enteritidis
P. aeruginosa
C. jejuni
S. sonnei
L. monocytogenes
E. coli
S. enteritidis
P. aeruginosa
C. jejuni
S. sonnei
L. monocytogenes
E. coli
S. enteritidis
P. aeruginosa
C. jejuni
S. sonnei
L. monocytogenes
E. coli
S. enteritidis
P. aeruginosa
C. jejuni
S. sonnei
L. monocytogenes
E. coli
S. enteritidis
P. aeruginosa
C. jejuni
S. sonnei
L. monocytogenes
E. coli
S. enteritidis
P. aeruginosa
C. jejuni
S. sonnei
L. monocytogenes
E. coli
S. enteritidis
P. aeruginosa
C. jejuni
S. sonnei
L. monocytogenes
E. coli
S. enteritidis
P. aeruginosa
C. jejuni
In Tables 19-30 each figure on average bacteria count per bird represents the average of 5 birds.
The objective of this study was to determine the effect of bleach microbiocidal control (20 ppm Cl2 equivalent) and of microbiocidal control with 1,3-dibromo-5,5-dimethyl-hydantoin (DBDMH) on organoleptic taste evaluation of both breast and thigh meat. Formal trained taste panel evaluation was conducted. The trial was conducted using 49-day old birds which were processed unchallenged with external sources of bacteria and under sterile conditions.
A total of 120 birds were used in this study. Sixty of the birds served as a control group. These were subjected to treatment in a chill tank containing Clorox® bleach at a 20 ppm Cl2 equivalent level. The other 60 birds were treated in a chill tank in the same fashion except that the chilling water contained DBDMH at the level of 20 ppm Cl2 equivalent. During the 1.5 hour chilling period in the chill tank, the contents of the tank were vigorously stirred every 10 minutes. After the 1.5 hour chilling period, the whole birds were individually bagged and placed in a commercial refrigerator for 20 days of storage. After aging, individual breast and thigh samples were cut and cooked to an internal temperature of 190° F. Taste evaluation was determined using 10 trained taste panel experts. A Ranking System (“1” or “2”) was used where “1” represents the better tasting sample. A simple average of subject evaluations or rankings per person were used. Statistical evaluation was employed by using each subject as a block employed delta 0.05.
Tables 31 and 32 set forth the results of these taste evaluations.
1S(subject) = trained taste panelist subject number.
2NOTE: Means within a row without a common superscript are significantly different (P < 0.05) as determined by Least Significant Difference.
1S(subject) = trained taste panelist subject number.
2NOTE: Means within a row without a common superscript are significantly different (P < 0.05) as determined by Least Significant Difference.
The objective of this study was to determine the effect of Clorox® bleach and 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) on individual carcass bacteria field strains after 1.5 hour in a chill tank solution and spoilage 20-day shelf life longevity (caused by bacteria contamination) in a Graded Level Study Model. After normal processing of 56-day-old birds, carcasses were immersed first in a warm bath containing 104 CFU's per mL Escherichia coli, 104 CFU's per mL Salmonella enterilidis, 104 CFUs per mL Pseudomonas aeruginosa, 104 CFU's per mL Campylobacter jejuni, and 104 CFU's per mL spoilage bacteria each from two strains (Listeria monocytogenes and Shigella sonnei). Carcasses were then immersed in a chill tank “soup”, containing normal organic fluids (blood, fat, skin, and meat particles) and containing various disinfectants (termed test materials). These tests were conducted at pH 8 (adjusted by trisodium phosphate). Skin pigmentation (Minolta Color Meter L value or Lightness, a value or redness and b value or yellowness) was determined before and after processing. Post-chilling skin bacteria of various strains were determined over a 20-day period. Sensory evaluation was determined to demonstrate spoilage times and shelf-life. After salmonella infection in chill tanks, USDA HACCP salmonella detection was simulated and reported.
The materials tested and the experimental design of these test were as summarized in Table 33.
A DBDMM stock solution and DBDMH test solutions of the concentrations specified in Table 33, a bacteria stock solution, and a “chicken soup” were prepared as in Example 3. In addition, the bacterial broth treatments, the whole bird wash sampling procedure, and the methodologies used for quantitative or qualitative determinations for bacterial organisms were conducted as in Example 3.
The trial events and experimental design used in this group of tests were the same as in Example 5 with the following exceptions:
Tables 34-37 summarize the results of this group of tests.
1Twelve (12) per 51 or less is considered to be statistically acceptable by USDA HACCP standards. A total of 102 birds were used to determine salmonella positive samples and a simple average determined.
1Four (4) or more per treatment is considered to be highly objectionable.
1Continuous scale for non-structured fresh inside carcass odor sensory attributes ranges from value 1.0 (the lowest intensity) to value 9.0 (the highest intensity). NOTE: Means within a row without a common superscript are significantly different (P < 0.05) as determined by Least Significant Difference.
2Five (5) or more is considered to be highly objectionable.
1NOTE: Means within a row without a common superscript are significantly different (P < 0.05) as determined by Least Significant Difference.
2Skin pigmentation (Minolta Color Meter L value or Lightness, a value or redness and b value or yellowness).
Results from the above tests on the effect of chill tank treatment on growth of Pseudomonas species on the chicken skin are graphically depicted in FIG. 1.
A study was carried out to determine the effectiveness of several microbiocidal compounds of this invention, as well as sodium hypochlorite when used as carcass rinses. The microbiocides of this invention used in this study were 1,3-dibromo-5,5-dimethylhy-dantoin (DBDMH), N,N′-bromochloro-5,5-dimethylhydantoin (BCDMH) and Stabrom® 909 biocide (Albemarle Corporation), a concentrated alkaline aqueous solution produced from bromine chloride and sulfamate anion (SSBC).
After normal processing of 56 day-old birds, carcasses were immersed first in a warm bath containing 104 per mL Escherichia coli, 104 per mL Salmonella enteritidis, 104 per mL Pseudomonas aeruginosa, 104 per mL Campylobacter jejuni, and 104 per mL spoilage bacteria each from two strains (Listeria monocytogenes and Shigella sonnei). Carcasses were then immersed in a chill tank “soup”, containing normal organic fluids blood, fat, skin, and meat particles) and containing various disinfectants (termed test materials). These whole bird bacteria count tests were conducted at pH 8. The effect of the test compounds on skin pigmentation was determined by use of Minolta Color Meter L value or Lightness, a value or redness and b value or yellowness. Post-chilling skin bacteria of various strains were determined over a 20-day period. Spoilage, using sensory odors as a model, determined time required to create a putrid/ammonia-like odor. After salmonella infection in chill tanks, USDA HACCP salmonella detection was simulated and reported. Table 38 describes the test material dosages and overall design of this group of tests.
DBDMH and BCDMH stock solutions and diluted test solutions (20 ppm Cl2 equivalent), a bacteria stock solution, and a “chicken soup” were prepared as in Example 3 except that the Stabrom® 909 biocide concentrate was diluted by adding 30 mL per liter of water just prior to application. This diluted solution was sprayed on the birds, both inside and outside, in quantities of 200 mL per bird. In addition, the bacterial broth treatments, the whole bird wash sampling procedure, and the methodologies used for quantitative or qualitative determinations for bacterial organisms were conducted as in Example 3.
The details concerning the trial events used as well as the detailed experimental design used in these tests were the same as described in Example 6. The only exceptions
Tables 39-42 summarize the results of this group of tests. The effect of the chill tank treatment of this Example on growth of Pseudomonas species on chicken skin are graphically depicted in FIG. 3.
1Twelve (12) per 51 or less is considered to be statistically acceptable by USDA HACCP standards. A total of 102 birds were used to determine salmonella positive samples and a simple average determined.
1Four (4) or more per treatment is considered to be highly objectionable.
1Continuous scale for non-structured fresh inside carcass odor sensory attributes ranges from value 1.0 (the lowest intensity) to value 9.0 (the highest intensity). NOTE: Means within a row without a common superscript are significantly different (P < 0.05) as determined by Least Significant Difference.
2Five (5) or more is considered to be highly objectionable.
1NOTE: Means within a row without a common superscript are significantly different (P < 0.05) as determined by Least Significant Difference.
2Skin pigmentation (Minolta Color Meter L value or Lightness, a value or redness and b value or yellowness)
3All treatment skin pigmentation were measured on 120 birds, except for SSBC where only 10 birds were employed.
A number of tests have been carried out demonstrating the microbiocidal effectiveness of several microbiocides in eradicating or controlling various bacteria species of the types present in poultry processing systems.
One such series of tests involved determinations of microbiological control against Escherichia coli bacteria. Another set of tests involved determinations of microbiological control against Enterococcus faecium. In each case, comparative tests were carried out in the same manner utilizing the AOAC test method. Such test involves exposing a culture of the microorganism to various concentrations of a test solution prepared from an aqueous stock solution of the compound under test. At various time intervals the halogen in the test suspensions is chemically neutralized, and the amount of viable bacteria remaining is enumerated by plating onto nutrient agar and incubating for 2 days at 37° C. Results are expressed at the log10 colony forming units (CFU). The concentration of the compound required to achieve complete kill (i.e., no viable bacteria remain) within 30 seconds is determined in the test.
Table 43 summarizes the data obtained in the tests using respectively, 1,3-dibromo-5,5-dimethylbydantoin (DBDMH) and N,N′-bromochloro-5,5-dimethylhydantoin (BCDMH) and in which the microorganism in each case was Escherichia coli. It can be seen that 1,3-dibromo-5,5-dimethylhydantoin passed the test at one milligram of bromine, as Br2, per liter of water, as evidenced by the complete kill within 30 seconds, whereas 1,3-bromochloro-5,5-dimethylhydantoin required two milligrams of bromine, as Br2, per liter of water to achieve complete kill within 30 seconds.
Table 44 summarizes the data obtained in the tests using respectively 1,3-dibromo-5,5 methylhydantoin (DBDMH) and N,N′-bromochloro-5,5-dimethylhydantoin (BCDMH) and in which the microorganism in each case was Enterococcus faecium. Table 44 shows that 1,3-dibromo-5,5-dimethylhydantoin passed the test at one milligram of bromine, as Br2, per liter of water, as evidenced by the complete kill within 30 seconds, whereas N,N′-bromochloro-5,5-dimethylhydantoin required two milligrams of bromine, as Br2, per liter of water to achieve complete kill within 30 seconds.
Table 45 summarizes test results performed at MBEC Bioflim Technologies, Inc., Calgary, Canada on the effectiveness of various biocides on bioflim removal. The test procedure, developed at the University of Calgary, utilizes a device which allows the growth of 96 identical biofilms under carefully controlled conditions. The device consists of a two-part part vessel comprised of an upper plate containing 96 pegs that seals against a bottom plate. The bottom plate can consist of either a trough (for biofilm growth) or a standard 96-well plate (for biocide challenge). The biofilms develop on the 96 pegs. The device has been used as a general method for evaluating the efficacy of antibiotics and biocides towards biofilms. See in this connection H. Ceri, et al., “The MREC Test: A New In Vitro Assay Allowing Rapid Screening for Antibiotic Sensitivity of Biofilm”, Proceedings of the ASM, 1998, 89, 525; Ceri, et al., “Antifungal and Biocide Susceptibility testing of Candida Biofilms using the MBEC Device”, Proceedings of the Interscience Conference on Antimicrobial Agents and Chemotherapy, 1998, 38, 495; and H. Ceri, et al., “The Calgary Biofilm Device: A New Technology for the Rapid Determination of Antibiotic Susceptibility of Bacterial Biofilms”, Journal of Clinical Microbiology, 1999, 37, 1771-1776.
Six biocide systems were evaluated using the above test procedure and test equipment. Five of these systems were oxidizing biocides, viz., chlorine (from NaOCl), halogen (from NaOCl+NaBr), halogen (from BCDMH), bromine (from DBDMH), and chlorine (from trichloroisocyanuric acid), all expressed as bromine as Br2 in mg/L, so that all test results were placed on the same basis. The sixth biocide was glutaraldehyde, a non-oxidizing biocide.
These biocide systems were used to challenge biofilms of Pseudomonas aeruginosa (ATCC 15442). This is a Gram (−) bacterium which is ubiquitous in microbiological slimes found in many water systems. See in this connection J. W. Costerton and H. Anwar, “Pseudomonas aeruginosa: The Microbe and Pathogen”, in Pseudomonas aeruginosa Infections and Treatment, A. L. Baltch and R. P. Smith editors, Marcel Dekker publishers, New York, 1994. In the field of poultry processing, S. Notermans, J. Dormans, and G. C. Mead, Biofouling, 1991, Vol. 5, pages 21-36, report observation of biofilms in poultry slaughter houses by use of scanning electron microscopy.
In Table 45 the MBEC (minimum biofilm eradication concentration) results presented are for the one-hour biocide contact time used in the test. The values given for the halogen containing biocides are expressed in terms of mg/L of bromine as Br2. The data on the glutaraldehyde is in terms of mg/L as active ingredient. The data indicate that the DBDMH was more effective than any of the other biocides tested under these conditions with an MBEC of 1.4 mg/L of bromine, as Br2. In fact, only slightly more than one-half as much bromine from DBDMH was required to remove the biofilm as compared to the total halogen, expressed as Br2, that was required from BCDMH.
In another group of tests, the results of which are depicted in
The experimental conditions utilized in these tests involved use of an apparatus consisting of three parallel transparent PVC sampling pipes. These pipes were used for collection of biofilm (i.e., sessile or surface attached) bacteria samples; one as control pipe, one for a relatively low biocide concentration and the third for a higher biocide concentration. The biocide challenge in each case was divided into three phases. First was a 14-day inoculation. Next was a 48-hour disinfection period. Finally a 2-week recovery period was provided. The biocide under test was slug-dosed and during the fist hour of exposure, the concentration was adjusted to achieve the desired concentration level.
The source of the naturally-grown heterotrophic plate count (HPC) bacteria was sediment and associated water collected from the recirculating hot water system of a hospital. Filter cartridges were inserted into the hospital water system and after about two months a suitable amount of sediment had accumulated on the filters. The collected filter/water suspension was then harvested for culturing. The inoculum for the biocide challenge experiments consisted of dechlorinated tap water, HPC-cultured stock solution, and a nutrient supplement solution. The inoculum was incubated at 37° C. for 14-days prior to the start of the test. The inoculum along with additional dechlorinated tap water was introduced into the apparatus composed of the three parallel transparent PVC sampling pipes. This mixture was recirculated throughout the apparatus intermittently at the rate of 3.2 gallons per minute for 14-days to produce a consistent biofilm and planktonic HPC bacteria population.
Samples of these bacteria were collected at the end of the 14-day inoculation period before the biocide challenge. In each test, the HPC bacteria was then challenged with a specified level of abromine-based biocide, and samples were taken at 1, 2, 3, 12, and 48-hour intervals. These samples were taken by swabbing the inner surface of a prepeasured section (length, {fraction (17/32)} inch) of the transparent PVC sampling pipe. The swabs were vortexed for 1 minute in 5 mL of deionized water with 0.1 mL of a neutralizer (to remove residual bromine) before plating. Con currently, water samples were taken for enumeration of the planktonic HPC bacteria.
After the 48-hour biocide challenge period, the procedure involved providing the 2-week recovery period. The purpose of providing this recovery period was to determine how quickly the viable HPC bacteria that were still present repopulated both the biofilm and, in planktonic form, the recirculating water. Thus, the recirculating water was drained from the test apparatus and the apparatus was refilled with heat-sterilized tap water which was also allowed to recirculate intermittently as before. After 7 and 14 days the apparatus was resampled and biofilm and planktonic HPC bacteria were enumerated in the same manner as done previously.
The results of these test are presented in graphical for in the
In
The results depicted in
In
The test results depicted in
In the tests of
In the practice of this invention, combinations of different sanitizing steps using different microbiocidal agents, at least one of which is a microbiocide of this invention, preferably one or more bromine-based microbiocidal agents of this invention, can prove useful. For example, a microbiocide of this invention, preferably a bromine-based microbiocide of this invention, can be applied to or contacted with various surfaces associated with the poultry processing such as conduits, tanks (e.g., the scalding tank(s), chill tank(s), conveyor belts or conveyor lines, and the poultry carcasses themselves can be treated with an antimicrobial agent such as solutions or gels containing carboxylic acids (e.g., acetic or lactic acid) and/or peroxycarboxylic acids, such as peracetic acid, peroxyoctanoic acid, peroxydecanoic acid, or the like. Use of such carboxylic acids is described for example in U.S. Pat. No. 6,113,963. The result of such combined operations is highly effective sanitization. In fact, it is contemplated that this combination of operations will result in a greater extent of microbiological eradication than has been generally achievable heretofore, especially when the bromine-based biocide used is 1,3-dibromo-5,5-dimethylhydantoin and the carboxylic acid used is peracetic acid. Indeed the combined effect of these microbiocides maybe synergistic.
Another microbiocide which can be utilized in combined operations pursuant to this invention is trisodium phosphate, a material which according to Capita et al., Meat Science, 2000, 55 (4), 471-474, has been approved by the USDA as an aid to eliminate Salmonella on raw poultry carcasses. In the combined operations trisodium phosphate is applied to the poultry carcasses, and one or more of the microbiocides of this invention, preferably one or more of the bromine-based microbiocides of this invention, are utilized in sanitizing the equipment, instruments, and/or apparatus associated with the processing of the poultry. Also pursuant to this invention the combined operations can utilize chlorine dioxide treatments along with use of the microbiocides of this invention. Smith, Meat Processing, 1996, 35(10), 47 indicates that chlorine dioxide had been approved by the US FDA for use in poultry processing water, and in the practice of this invention one or more microbiocides of this invention, preferably one or more of the bromine-based microbiocides of this invention, are utilized in sanitation of various items of equipment, instruments, and/or apparatus utilized in the processing of the poultry, and chlorine dioxide is used to sanitize at least some of the poultry processing water.
Another way by which combined operations pursuant to this invention can be carried out involves administering to the digestive tract of the poultry a suitable biological pathogen-control agent, such as by including such biological agent in the drinking water for the fowl, or on or in the feed for the fowl. Illustrative biological pathogen-control agents which may be used in this manner include certain strains of E. coli described in U.S. Pat. No. 6,083,500. Thus in the practice of this invention, such a biological pathogen-control agent is provided to the fowl for consumption by drinking and/or eating, and a microbiocidally-effective amount of an aqueous solution of at least one microbiocide of this invention, which preferably is at least one bromine-based microbiocide of this invention, is used in disinfecting or sanitizing equipment, instruments, apparatus, and/or water used in the processing of poultry, and/or of carcasses and/or parts of poultry resulting from the processing of poultry.
Still another combined operation involves (i) treating the carcasses of the fowl with immobilized lactoferrin antimicrobial agents as described in U.S. Pat. No. 6,172,040 B1 and (ii) disinfecting or sanitizing all or a portion of the equipment, instruments, apparatus, and/or water used in the processing of poultry by contacting the same with a microbiocidally-effective amount of an aqueous solution of at least one microbiocide of this invention, which preferably is at least one bromine-based microbiocide of this invention.
Automated dispensing equipment suitable for use in dispensing the microbiocides of this invention has been described in the literature and to at least some extent is available in the marketplace. For a reference to such equipment, see for example U.S. Pat. No. 5,683,724 wherein an automated dispensing system is described.
While chemists understand what is meant by “aqueous” in connection with a solution or medium or the like, it is probably desirable to state for the benefit of those lawyers who may make it a profession to pettifog over every word someone uses, just what “aqueous” means. The adjective “aqueous” means that the solution or medium or whatever other noun the adjective modifies, can be water whether highly purified or of ordinary purity such as emanates from the faucet. Since we are dealing with processing of food, it stands to reason that one would not use sewer water or water containing lethal doses of poisons such as cyanide. Besides naturally-occurring trace impurities that may be present in, say, potable water in general, such as ordinary well water or municipal water, the adjective “aqueous” also permits the presence in the water of dissolved salts that are formed in the course of forming a bromine-based microbiocide in the water, e.g., by reaction between bromine chloride and sodium sulfamate in an overbased aqueous solution. In addition, “aqueous” permits the presence of small amounts of innocuous non-harmful, water-soluble organic solvents such as ethyl alcohol which can be used as a solvent for the 1,3-dihalo-5,5-dialkylhydantoin(s). Also “aqueous” permits the presence in the water of the amount of the halogen-based microbiocide itself to the extent that it may dissolve in the water, plus any dissolved reactant(s) that may remain after the reaction. Also the water may contain a few atoms that may dissolve from the vessel in which the reaction takes place, plus air-borne impurities that may find their way into the water. The point here is that the term “aqueous” does not restrict the medium or solvent to absolutely pure water—the aqueous solution or medium or the like can contain what would normally be present and/or reasonably be expected to be present in it under the particular circumstances involved when employing ordinary common sense.
Compounds referred to by chemical name or formula anywhere in this document, whether referred to in the singular or plural, are identified as they exist prior to coming into contact with another substance referred to by chemical name or chemical type (e.g., another component, a solvent, or etc.). It matters not what chemical changes, if any, take place in the resulting mixture or solution, as such changes are the natural result of bringing the specified substances together under the conditions called for pursuant to this disclosure. As an example, the phase “solution of at least one 1,3-dihalo-5,5-dialkylhydantoin” and phrases of similar import signify that just before being brought into contact with an aqueous medium such as water, the at least one 1,3-dihalo-5,5-dialkylhydantoin referred to was the specified 1,3-dihalo-5,5-dialkylhydantoin. The phrase thus is a simple, clear way of referring to the solution, and it is not intended to suggest or imply that the chemical exists unchanged in the water. The transformations that take place are the natural result of bringing these substances together, and thus need no further elaboration.
Also, even though the claims may refer to substances in the present tense (e.g., “comprises”, “is”, etc.), the reference is to the substance as it exists at the time just before it is first contacted, blended or mixed with one or more other substances in accordance with the present disclosure.
Except as maybe expressly otherwise indicated, the article “a” or “an” if and as used herein is not intended to limit, and should not be construed as limiting, the description or a claim to a single element to which the article refers. Rather, the article “a” or “an” if and as used herein is intended to cover one or more such elements, unless the text expressly indicates otherwise.
All documents referred to herein are incorporated herein by reference in toto as if fully set forth in this document.
This invention is susceptible to considerable variation within the spirit and scope of the appended claims.
This is a continuation-in-part of commonly-owned application Ser. No. 09/893,581, filed Jun. 28, 2001 now abandoned. Reference is hereby made to the following commonly-owned applications: application Ser. No. 09/088,300, filed Jun. 1, 1998, now U.S. Pat. No. 6,068,861 issued May 30, 2000; application Ser. No. 09/296,499, filed Apr. 22, 1999, now U.S. Pat. No. 6,110,387 issued Aug. 29, 2000; application Ser. No. 09/323,348, filed Jun. 1, 1999, now U.S. Pat. No. 6,303,038 B1 issued Oct. 16, 2001; application Ser. No. 09/404,184, filed Sep. 24, 1999; application Ser. No. 09/442,025, filed Nov. 17, 1999, now U.S. Pat. No. 6,306,441 issued Oct. 23, 2001; application Ser. No. 09/451,319, filed Nov. 30, 1999; application Ser. No. 09/451,344, filed Nov. 30, 1999, now U.S. Pat. No. 6,352,725 B1 issued Mar. 5, 2002; application No. 09/456,781, filed Dec. 8, 1999, now U.S. Pat. No. 6,495,169 B1 issued Dec. 17, 2002; application Ser. No. 09/483,896, filed Jan. 18, 2000, now U.S. Pat. No. 6,448,410 B1 issued Sep. 10, 2002; application No. 09/484,687, filed Jan. 18, 2000, now U.S. Pat. No. 6,508,954 B1 issued Jan. 21, 2003; application No. 09/484,844, filed Jan. 18, 2000; application Ser. No. 09/484,891, filed Jan. 18, 2000 now U.S. Pat. No. 6,495,698 B1 issued Dec. 17, 2002; application Ser. No. 09/484,938, filed Jan. 18, 2000, now U.S. Pat. No. 6,565,868 B1 issued May 20, 2003; application No. 09/487,816, filed Jan. 18, 2000; application Ser. No. 09/506,911, filed Feb. 18, 2000, now U.S. Pat. No. 6,511,682 B1 issued Jan. 28, 2003; application Ser. No. 09/658,839, filed Sep. 8, 2000, now U.S. Pat. No. 6,375,991 B1 issued Apr. 23, 2002; application No. 09/663,788, filed Sep. 18, 2000, now U.S. Pat. No. 6,348,219 B1 issued Feb. 19, 2002; application Ser. No. 09/663,948, filed Sep. 18, 2000, now U.S. Pat. No. 6,299,909 B1 issued Oct. 9, 2001; application Ser. No. 09/732,601, filed Dec. 7, 2000, now U.S. Pat. No. 6,506,418 B1 issued Jan. 14, 2003; application Ser. No. 09/775,516, filed Feb. 2, 2001, now U.S. Pat. No. 6,641,828 B1 issued Nov. 4, 2003; application No. 09/778,228, filed Feb. 6, 2001, now abandoned; application Ser. No. 09/785,890, filed Feb. 16, 2001; application Ser. No. 09/893,581, filed Jun. 28, 2001, now abandoned; and application Ser. No. 09/974,622, filed Oct. 9, 2001, now U.S. Pat. No. 6,652,889 B2 issued Nov. 25, 2003. Reference is hereby made to Application No. 10/028,631, filed Dec. 21, 2001, which is presently owned by the other of the original joint owners.
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| WO 8802987 | May 1988 | WO |
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| Number | Date | Country | |
|---|---|---|---|
| 20050100643 A1 | May 2005 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 09893581 | Jun 2001 | US |
| Child | 10029329 | US |
